On the environmental dependence of the cluster galaxy assembly timescale



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Carretero, C. and Vazdekis, A. and Beckman, J. E. and Sánchez Blázquez, P. and Gorgas García, Francisco Javier (2004) On the environmental dependence of the cluster galaxy assembly timescale. Astrophysical journal, 609 (2). L45-L48. ISSN 0004-637X

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Official URL: http://dx.doi.org/10.1086/422749


We present estimates of CN and Mg overabundances with respect to Fe for early-type galaxies in eight clusters over a range of richness and morphology. Spectra were taken from the Sloan Digital Sky Survey Data Release 1 and from William Hershel Telescope and Centro Astronómico Hispano-Alemán observations. Abundances were derived from absorption lines and single-burst population models, by comparing galaxy spectra with appropriately broadened synthetic model spectra. We detect correlations between the [Mg/CN] and [CN/Fe] values and the cluster X-ray luminosity. No correlation is observed for [Mg/Fe]. We also see a clear trend in the richness and morphology of the clusters. This is interpreted as giving varying formation timescales for CN, Mg, and Fe and a varying star formation history in early-type galaxies as a function of their environment: intermediate-mass early-type galaxies in more massive clusters are assembled on shorter timescales than in less massive clusters, with an upper limit of ~1 Gyr.

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© 2004. The American Astronomical Society. All rights reserved.
The authors thank A. Aguerri, X. Barcons, L. Carigi, C. Gutiérrez, R. Peletier, and the anonymous referee for useful comments. We acknowledge grant AYA2001-0435 from the Spanish Ministry of Science and Technology. The SDSS is managed by the ARC for the Participating Institutions.

Uncontrolled Keywords:Color-magnitude diagram; Digital sky survey; Population synthesis; Elliptic galaxies; Distant clusters; Feature indexes; Evolution; Sample; Stars; Abundances
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:36914
Deposited On:13 Apr 2016 15:04
Last Modified:10 Dec 2018 15:05

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